Nut tapping machine



'Aug.15,1944. H QTANGO'WSK.' 2,3- =6,100

. v NUT TAAPPING MACHINE;

Filed May 22, 1943 2 sheets-sheet 1 INYEN-ron HENRY C. TANGOWVSKI 15 1944 Y H.c.TANGow sKl Y 2,356,100

NUT TAPPING MACHINE Filed may 22, 194sl 2 sheets-sheet 2 Y Il y" l Il INVENTOR HENRY CIANGOWSKI BY l /V my ATTORNEY Patented Aug. 15, 1944 NUT TAPPIN G :MACHIN E Henry c. Tangowski, Elizabeth, N. .1., assigner io' Elastic Stop Nut Corporation of America, a corporation of New Jersey f' Application May 22, 1943, serial No. 487,9'9a .1

1 ciaimf (C110-139) This invention relates to machine tools and methods of securing better performances ofv the same. 'I'his invention more particularly relates to machine tools'such asy automatic tappers,

reamers, or the like, whereina plurality of'arti- 'cles pass, in succession, along a predetermined path through a rotating or moving tool holder.

The principles of this invention are applicable,

for example, to an automatic nut tapper .of a type wherein the tap is provided with a threaded entrance section and a curve leading to the discharge section, which is disposed at an angle, such as 90?, to the entrance section. A portion of the tap, including theI cu'rve and the discharge section, lies in a passage in a rotatingchuck, the

tap rotating with the chuck` and successive nuts being pushed onto the threaded section of the tap. The nuts move along the tap through the passage, contacting the walls of the passage to hold the tap in position, and are discharged from wherein restraining forces are applied at a pointl or points such that numerous previousdiillculties "are overcome; Further Aobjects `and the novel features ofthis invention will Abecome apparent from'y the following-,description companying drawings, in :which:

Fig. 1 isa perspective view of an'automatic tapping apparatus, including an embodiment' of and acthis invention;

Fig. 2 isa longitudinal section of the apparatus Fig. 3 is across-section taken along `line 3 1 otfFig. 2, through the exit end ofthe passage'ln atap'chuck;A

Fig. 4 is a longitudinal view vof thevchuck; vand y Fig.l 5k is a fragmentary perspective 'view of va portion of the chuck aroundtheentrance .to the tap passage, to illustrate the manner in which the exit end of the passage in therside of the f chuck.

In such a. tapper, difficulty is experienced in achieving a uniform discharge of nuts. It isimportant that such discharge be uniform-otherwise the nuts tend to jam on the top. or too many articles are discharged, thereby removing the only means for holding the rtap accurately in alignment. Thus, a primary object of this invention is to provide an improved method and suitable means for obtaining a substantially uniform 'flow of articles from a tool whichV is held in alignment in a passage in a moving tool 'holder by articles passing therealong.

Other objects include the provision of means for producing substantially equalized detaining forces on an article tending to be discharged from such a tool; the provision of such means which, when the detalning force is. overcome, tends toeject the article; the provision of'means which will tend 'to keep anl article in alignment in a passage in a tool holder in which the tool is disposed; and the provision of a'detainer of the foregoing type which is relatively simple in construction and is. easily adaptable to varied forms of tool holders, being particularly adaptable to a rotatable chuck having a passage for receiving a tap with a 90 bend therein.v Additional objects include the provision of an improved method whereby articles may be discharged in a more effective manner from a passage in a moving holder for a tool along which the articles pass; the provision of such a method whereby restraining forces are morefeiectively applied; and the provision of such av method the nuts are movedinto alignment with the tap passage as, they enterthe rotating chuck.

In automatic. tapping apparatus of atype to which the principles of this invention are particularly applicable, as shown in Fig. 1,. a plurality of nuts'N are pushed onto va tap 'I' by areciprocating hexagonal plunger il).` The `nuts-arev fed to the plunger through .a chute Il,- leading-from a selective hopper l2, and are held fromfrotating in a polygon-al space formed by jaws i3, aportion of the jaws beingomitted in Fig. 1, for clarity of illustration. The tap T -is provided-withr a threaded entrance section I4 atone end, and

an exit section l5 at the oppositeend, disposed at b to the entrance section,.with1asmooth axial section i6 and a curve ll therebetween and adjoining the entrance andexit sections, respectively.Y vThe tapis rotated by a chuck C, the tap lying in passage P in the chuck, `which follows in general the configuration of the tap.

As successive nuts larefed ontov the `rotating tap, threads are. Vformed'ln the bores thereof, and

Vas the nuts pass fupfthe tap and beyond the threaded entrance" section, they push the precede ing Vnuts along' -the tap and into the rotating chuck. The nutsK are .brought .into alignment with the side wallsof passage P by anear 1,8, in a mannerdescribed` later.

The tapit'self does not touch the side walls of the passage vP, being 'held in alignment therein by the column of nuts Aseach nut comes-to the exit section l5 of the tap, after moving around curve Il, it tends to be thrown oif and out of thepassage by centrifugal force,l as in Fig. 1. As the exit section, as well as the axial section, of the tap would otherwise soon become devoid of nuts-tbus leaving thetap unsupported, tor-:become misal-igned-andthen become yoverestressed-and crack. ory breakin thethreaded-:sec-

tion-itis necessaryttorestrain movement of' the .nuts off the r:exit section,='anddepend ,upon the Yforce of-succeeding -nu-tsmuslrxed '.along'athe: tap i from the threadedsection to'dischargenutsifrom 4thetap. e'

In accordance with .fthe ymethod of.this-inven tion, rsubstantially equalirestraining forces .are exerted against. an 2 article fat two or more.v points spaced symmetrically aboutzthe passage through '.which the article passes, and at points spaced Ysufiiciently from vi,he.exit:end of.. the passage so pth'at afterthe restrainingforce overcome,` the .article ywill travelalong at ileast a portion of the. `tool Ibefore being nallydischarged. .In'thecase of vaxtool :having an exit-section. disposedfat. Yan angleto 'thefentrance section, .as inthe case #of x.the tap T, .thepoints at which the-.restraining Aforces are exerted. are preferably sunlciently-..close to: the vend .of the tool, .so that Athe articles Awill contact the wall lof the -:passage Afora Vsuillcient distancealong .the -exit section of the `toolto maintain .the .tool .accurately inlalig'nment. "The restrainingcforces1ere .applied at two vor more `points kdisposed symmetrically aboutpthe pasmegan-to .prevent any terldencyfor turning or misalignmentvof .thefarticla "Inthe case ot articles -such as.nut-lN anchtools'suchl` as tapT, the Vrestraining forces are preferably sufllciently great to overcome the tendency for .the `nuts .-to be thrown out of the passage and off .the tap by centrifugal. nforce, yet not-eso' lstrong as .to :hinder unduly fthe re'ady movement of nuts alongthe `tap. Forfexample, the restraining forcesmaybe suicientto prevent'a'nutiirom being discharged from the .tap :by centrifugal force, but readily permit anut fto be .discharged` when it ispushed 4along lby another nut moving from the threaded :entrance section YI4 .to 'theiunt'hreaded axial section |6,;albeit insuicient vto vcause the Vnuts to crowdtogetherwand jam .along` curve I1.

In further accordance with this invention, ad-

ditional #forces mayhbe imposed -upon .the article subsequent .to .or :at thea'time the restraining` Aforces.l are overcome, whichzadditional forces :tend

lto eject f thearticIe' :from the litool holder. Y i Such additional forces are 'preferabl-y also vexerted at two ornore `points :disposed symmetrically Yabout Jthe :periphery .of the article -and lequidstantly from the end of .the :passage,.but. spaced-sumciently .fromtheendo'f `the tool so that each article Vwill .travel along sat gleastI a small 'portion .of the ecit end of the toolbefore beingnally Afdischarged. :Such .forces cause "the yarticles :to be quickly. evenly, `and uniformly discharged, 'there- -by further overcomingany tendency for `misalignlmentor:twistingiasfthe end of @the tool is reached.

.'Also, .when -the last .nut` is -quickly .discharged after. fthe `restraining .force is overcome, zthe. next .fnutfmovesveasi-lyfand vwithout .hindrance-up to the Vrestraining. means.

In an `embodiment vadapted to carry out `=the method of this 1invention,..as illustrated 3in1 Figs.

l'2 4.to 4, inclusive, :the VvChuokC is providedwwith resilient restraining'meansplconstructed in .accordance with lthis invention and disposed .adjacent Ithe end. of `passage P.- Ifor exerting restrain- .y ing forcespirom'zatfIeaSttWosides upon *thelast i nut 12li-on the tap. Such-restraining:meansmay comprise afpainof similar-or substantiallyiden- -Itical :detent i-balls A2 I :disposed Von opposite sides o'f :the passage andpressed inwardly by springs Z2,.alsopreferably similar .or substantially 4iden- ...frenetico :fromftheend ofthe tap, so that the nut 20 will '.haveflittle opportunity Vto become misaligned in overcomingthe-restraining force, but the balls A.rarealsospaced a sulicient distancefrom the end of curve lI7! to permit-nut 20 and the next succeedingnutli to maintain the exit end of the taprinthe` desired spaced'relation to the passage.

When the restraining force is overcome and the nutZIItm-ovesalong the tap, the detent balls will veject nut `20 with a snap. action, and simultaneously-hold the nut `23, which then becomes the 1a.st=nut, until another .nut moves from the threaded section I4 onto Unthreaded section I 6.

'Referring .again to more conventional details, chuck `C lis secured to the overhanging end of a shaft`25pwhich is rotated by suitable means, and

'is supportedadjacent the chuck by a bearing I'26,;aswinf.'Fig. .1, which may comprise part of a ycastingvforminga supporting housing 21. Housing "21 (onlyithe lower half of which is shown in Fig. l) enotfonly provides support for the parts,

'but-a. portion thereof surrounds the chuck, t0 .catch the-nuts discharged therefrom. The nuts "mayfowfrom the vhousing'to a' suitable trough,

bin, or other vcollecting device.

.Plunger II) is rreciprocated, 'through a rod 28, by va crank arm which may be actuated by Vsuitablefknown mechanism. The rate and amplitude of :.reciprocation ofarm 29 are adjustable in any `weil-known manner, while the longitudinal position of plunger IU `is adjustable by a threaded connection between rod 28l and the plunger. The

reciprocationof' plunger I0 is adjusted so that a ,nut will *bexpushed ontothe tap, the plunger .will withdraw, 'another nut will fall into Yplace vbefore. theplunger from the Afeed'chute II, and

.the Aplungerrwill push thisnut onto the tap,

.leaving `a suflicient vdistance between nuts so that theydo-n'ot become jammed on the threaded entrancesection I4.

.As the nuts move along threaded section I4,

they vare -prevented .from rotating by jawsv I3, but

.after the .nutspass from'the threaded entrance `section I4, theyarefre'e to begin rotating or spin- .ning on the smooth axial section I6. .:thepnuts :normally do not begin rotating at the .same -rate .asthe tap and chuck until they'reach '-fear/I'B. y.AsinFig 5,.ear vI8 is provided with a beveled edgeiu to provide a more gradual catch- However,

:ing :of the nut-*which is rotating in the same directionassthe chuck .but normally at a slower tical. PBa'lls 2l arc -spaced -a sufficient .distance-175 rate, v.so :that it tends to vrotate relative to the .chuck ;in the .direction of the arrow 3|. At the same time, fboth the .nut and the chuck are rotating inthe direction of the arrow 32-and as the-ear. I8, as it were, catches up with the nut. .'theunderside of :the ear rotates .the nut to bring ..thecnutinto .alignment with the walls of passage?.

Chuck.'Cincludesa vblock 35 to which is hinged a cover"36'whichrmay be secured in the closed position .by suitablevmeanS, such as a lmachine "Passage 'P may be rectangular in ysha.peso .that two opposite sides of the hex of nuts l'Nwill .engage the upper and lower walls of the passage, the .nuts thereby being held from .turning and also keeping tap T in alignment in one .transverse direction, and so that the meet- Ying edgesof the other two pairs of sides of the hexsof lthe'nuts will contact the side walls of the v.passage along tap sections I5 and I6, to main- .'.tamitheztaplin alignment in the other transverse ...and :the flongitudinal directions.

The side walls ofzthevpassage may, if desired, follow the curve I1, butrneed not'doso, as shown in Fig. 2, since the upper and lowerlwalls prevent the nuts from. turning in moving around the curve, and the tap is already held in alignment, by other wall portions of the passage, in the three directions `corresponding to the X, Y, and Z conventional geometrical axes.

The upper and lower walls of the passage are formed by a pair of plates 38 and 39, plate 38 being attached to cover 36 and plate 39 to block 35 in a suitable manner, as by machine screws. Ear |8 may be formed as an extension of-plate 38, or secured thereto in a suitable manner. The side walls of passage P are formed by a pair of spacing blocks 40 and 4|, and the front face 42 of block 35. More specifically, one side Wall of the passage along axial tap section I6 is provided by inner edge 43 of block 40, whilethe opposite side wall is provided by an inner edge 44 of block 4|; and one side wall of the passage along exit tap section l5 is provided by another inner edge 45.

Again in accordance with this invention, balls 2| extend through circular apertures 50 in plates 38 and 39, which are apertures countersunk on the inside to permit a suiiicient portion of the balls to extend through. The balls are disposed` in sockets 5| in block 35 and cover 36, respectively, which sockets permit a slight lateral and greater axial freedom of movement. Springs 22 extend through tapped holes 52 into engagement with the balls, and are held in place and compressed by set screws 53.

The restraining forces on. the opposite sides of the nut may be equalized by providing springs having substantially equal' compressive properties, and/or adjusting the set screws so that substantially the same force is exerted on each ball.

In addition, upon any change in the operating conditionssuch as due to nuts formed of diilerent material necessitating a different/rate ofrotatlon of the tap, which produces a change in the centrifugal force tendingto throw nuts out of the passage-the set screws may-be adjusted, or springs of different properties used, to alter the restraining force of the 'balls to obtain the desired result-i. e., hold the end nut onthe tap until a new nut is pushed on from the threaded section".

, The restraining means of this invention has many advantages. Not only is an even flow of articles assured, but also the tool itself is maintained more accurately in alignment, since the equalized forces exerted -by restraining means constructed in accordance with this invention are `transmitted :back down the line of articles extending around the curved portion of the tool. The specic embodiment of this invention herein described also has particular advantages.

It-is relatively easy to provide a chuck with detent balls and springs of thel type described; also, such balls and springs are relatively simple to adjust and take up very." little space. In addition, after the restraining force is overcome,

detent balls-orequivalent round-headed pinsv y iserninimized, and newly tooled surfaces, such asx the threads of nuts N, arel not damaged by the v article being twisted about the end of the tool upon leaving. i

Although a specic embodiment of this invention has been described with particularity, it will be understood that numerous variations are possible. For instance, round headed pins may be utilized instead of.balls; the springs may have any desired form or shape; other means of exerting a restraining force,` such as hydraulic or the like, may be utilized; and the construction of the chuck may be altered, with corresponding variations in the vapplication ofl the principles of this invention. Also, the principles of Vthis invention are applicable to different types of sapparatus, other than tappers, such as drills, reamers, and the like. It will be further understood that other changes may be made without de.

. in cross section, conforming to sides of said nuts,

said ear presenting a substantially at surface in alignment with one side of said chuck passage and also a beveled edge, whereby when a nut is not properly positioned when it' arrives at said ear, it will be partially rotated thereby and.

aligned with said passage.

HENRY C. TANGOWSKI. 

